How to measure your chainsaw bar? This is a very common question that our readers want to know so we’ve put together this guide, filled with facts and advice on measuring your chainsaw bar.
How to Measure Your Chainsaw Bar?
When planning to replace your bar or chain, you need to understand the terms and measurements used. Many folks travel to their local chainsaw expert with a sample in hand and explain what they need. Yet, it is a lot simpler to do it online and save some gas at the same time. The only provision is that you must be able to specify the bar accurately, this makes online ordering straightforward and safe.
Some manufacturers engrave or print the necessary information on the bar near the drive end. To facilitate the correct replacement, the part number is usually stamped on the bar too. Should you plan on using another brand, or different chain type, the additional information that’s provided will come in handy. They generally provide the pitch, followed by a graphic of the called length, gauge and drive link count. The content and style varies from one manufacturer to another, but it provides all the information you need to order a chain or bar.
If this information is not legible or not provided, you have to determine this yourself. I believe that this guideline will be invaluable in helping you achieve this.
How to Measure the Chainsaw Bar
The bar has two length measurements, the Called length, also called the cutting length and the total length of the bar. The called length is measured when the bar is mounted to the chainsaw, it is the part of the bar that’s used for cutting.
Called length or Cutting length
You measure the distance from the point where the bar first emerges from the chainsaw’s casing to the tip of the chainsaw bar. You may need to round that measurement up to the next inch. This is the called length or cutting length of the bar. The most commonly used bar length measurements on domestic type chainsaws are 14, 16, 18 and 20 inches.
Bar overall length
The overall length of the bar is measured from the tip of the bar to the mount-end of the bar.
Why is bar length worth knowing? When replacing the bar with one from another manufacturer, or a specialist bar, you must ensure that it is suitable for the chainsaw. When replacing it with one that’s longer or shorter, check the chainsaw manufacturer’s specifications to make sure the chainsaw can handle the bar size. When a longer bar is fitted, the chain load is increased. The engine has to work harder to overcome the additional load. You chainsaw may not be able to handle the extra length. This means that you would have wasted your money.
With the called and overall length determined, we still need to measure the pitch and gauge. To replace the chain you also need the link count.
What is Chain Pitch?
The pitch refers to the pitch of the chain and determines the chain size. If a nose sprocket is fitted to the bar, it must have the same pitch as the chain. You determine the pitch by measuring the distance between any three consecutive rivets on the chain. The rivets are the small, round pegs/studs that hold the chain segments together. You measure from anyone, skip the second, to the third. Now divide that number in half to get your chain pitch.
What is Gauge?
Gauge is the width of the drive links that run in the groove of your guide bar. This dimension must be determined exactly. If the chain fits too loosely, it will be unstable, it will wobble from side to side. It also won’t transfer the lubrication to the bar, causing it to wear faster. A chain that’s too wide will not fit into the groove of the bar. The usual gauge sizes are 0.043, 0.050, 0.058, and 0.063 inches.
To check the bar gauge when there are no identification numbers, you can use two methods. Before you measure the gauge, clean out the groove with a scraper or putty knife. The best method is to use three feeler gauges together to find the actual dimension. Measure down deep, past the initial 3/32″ where the wear is greater than it is in the recess of the groove. The second method is to use calipers, it is not as accurate because you cannot get down deep into the groove. To get the closest reading measure the chain links as well.
VIDEO | Which Chainsaw Bar is Right for You?
Types of Chainsaw Bars
Sprocket nose bar
A sprocket nose bar has a sprocket at the nose that the chain rides on to reduce friction. The number of teeth on the bar tip sprocket is a vital specification of a bar with a sprocket nose. Sprocket noses with less than 11 teeth are less prone to kickback than models with 11 or more teeth. The cutting performance increases with more teeth, especially when working with the bar nose.
Hard nose bar
A special purpose bar designed for abrasive (dirty) conditions where the sprocket nose may jam. A sprocket nose bar is more efficient, but the power reduction when using a hard nose is not excessive.
These bars consist of different layers of material to reduce the weight, extend service life and improve the rigidity of the bar. Laminated bars are said to be more prone to spreading the rails of the groove and bending, while solid bars are considered stronger. The general feeling is that if you use bars under 20 inches, the laminated type is a better choice. The chainsaw feels lighter with improved balanced. For occasional use, a solid bar may not be worth the expense.
Laminated bars with a nose wheel
Laminated bars generally have a gentle curve and a small nose radius that reduce the risk of kickback and facilitate good cutting control. Most chainsaws designed for 10 to 20-inch bars use laminated bars with a nose sprocket.
Solid steel bars are intended for professional use and cutting hardwood. Some have a replaceable nose since the bar nose wears out faster than the bar itself.
When the chainsaw is used in very sandy, dusty conditions like cutting thick bark, solid bars are the better solution. Chainsaw vendors generally offer solid bars in sizes 30 to 42 inches.
Solid bars with replacement tips
Some solid bars have a replaceable bar nose, generally used on long bars to reduce the load on the bar tip. This type of tip uses a high-quality roller bearing that carries the load of the chain around the nose. Replacement tips are available as spare parts, and are fitted with rivets that are driven out to replace the tip.
Extra-long chainsaw bars
Specialist bars include extra-long bars crafted from solid, high-tech titanium alloy steel with precision-ground grooves. These bars are more durable and come in lengths from 44 to 84 inches, with replaceable sprocket noses.
Extra light bars
These chainsaw bars are manufactured to be as light as possible, typically 18% lighter than conventional bars. This makes them easier to maneuver, often used on top handle chainsaws for pruning and working in treetops.
Double-ended chainsaw bar
A double-ended chainsaw bar is used for milling. Generally powered by two chainsaws, it requires two operators, and it’s used with a special jig and support rails. It takes a long time to set up but has the advantage of being used on a felling site.
Specialty carving bars
These bars are laminated bars with a small sprocket at the nose, reducing the kickback effect. Tips with a radius of 7mm to 22mm are typically used as carving bars. They are designed for the most delicate detail work and used with the smallest of chains. These bars are to be used on small, low powered saws. An example being the Cannon Carving Dime tip.
A narrow kerf bar and chain is used on most of the smaller chainsaws. It cuts a narrower kerf which requires less power when cutting. With its reduced weight and narrow cut, it can cut faster when compared to a standard 3/8-inch pitch, .050-inch gauge, low-profile chain. The weight of the cutting attachment is also reduced, something which is appreciated by arborists.
VIDEO | Measure Bar & Chain using Oregon Measuring Tool (556418)